title: [Osteoclasts and early bone remodeling after orthodontic micro-implant placement].
abstract: OBJECTIVE
  To observe the incidence of osteoclasts during early bone remodeling after orthodontic micro-implant placement.
  
  
  METHODS
  Twenty New Zealand rabbits were randomly allotted into 4 groups. One micro-implant was implanted proximal to the epiphyseal plate of the tibia. Animals were sacrificed on day 3, 7, 14 and 28 (n=5). The sequence of histological changes around the micro-implants were evaluated by hematoxylin and eosin (HE) staining. Osteoclasts were identified by TRAP staining. The differences of the number of the osteoclasts among each time point were analyzed by one way ANOVA with SPSS 19.0 software package.
  
  
  RESULTS
  After 3 days of implantation, a large number of erythrocytes, inflammatory cells, mesenchymal cells and bone debris were seen at the implant bone interfaces. Few osteoclasts were observed. On day 7, granular woven bone was formed and some osteoclasts were found in the Howship's lacunae. New bone formation and mineralization were apparent on day 14. Meanwhile, large amounts of osteoclasts were found in the latticed woven bone. On day 28, woven trabeculae with lamellate structures connected to lamellar bone and fewer osteoclasts were identified. Semi-quantitative analysis showed that the number of the osteoclasts was at peak on day 14. There were significant differences among each time point (P<0.01).
  
  
  CONCLUSIONS
  Osteoclast activity is closely related to bone formation and remodeling after micro-implant insertion.
authors.affiliation: DDepartment of Orthodontics, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology. Shanghai 200011, China.E-mail:zhangwei860920@126.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Jia-jia
authors.initials: JJ
authors.lastname: Guo
authors.forename: Wen-qian
authors.initials: WQ
authors.lastname: Zhu
authors.forename: Guo-hua
authors.initials: GH
authors.lastname: Tang
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D010010:Osteoclasts; D011817:Rabbits; D013977:Tibia